package com.codesdream.ase.service;

import com.codesdream.ase.component.permission.ASEPasswordEncoder;
import com.codesdream.ase.component.permission.ASEUsernameEncoder;
import com.codesdream.ase.component.permission.UserRolesListGenerator;
import com.codesdream.ase.exception.UserInformationIllegalException;
import com.codesdream.ase.exception.UserNotFoundException;
import com.codesdream.ase.exception.UsernameAlreadyExistException;
import com.codesdream.ase.model.information.BaseStudentInfo;
import com.codesdream.ase.model.permission.User;
import com.codesdream.ase.repository.permission.UserRepository;
import javafx.util.Pair;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collection;
import java.util.List;
import java.util.Optional;
import java.util.UUID;

@Service
public class UserService implements IUserService {
    @Resource
    UserRolesListGenerator userRolesListGenerator;

    @Resource
    UserRepository userRepository;

    @Resource
    ASEPasswordEncoder passwordEncoder;

    @Resource
    ASEUsernameEncoder usernameEncoder;

    @Override
    public List<User> findAll() {
        return (List<User>) userRepository.findAll();
    }

    @Override
    public Optional<User> findUserById(int id) {
        return userRepository.findById(id);
    }

    @Override
    public User findUserByUsername(String username) {
        Optional<User> user = userRepository.findByUsername(username);
        if(!user.isPresent()) throw new UsernameNotFoundException(username);
        return user.get();
    }

    @Override
    public Pair<Boolean, User> checkIfUserExists(String username){
        Optional<User> user = userRepository.findByUsername(username);
        return user.map(value -> new Pair<>(true, value)).orElseGet(() -> new Pair<>(false, null));
    }

    @Override
    public Collection<? extends GrantedAuthority> getUserAuthorities(User user) {
        return userRolesListGenerator.generateRoles(user);
    }

    @Override
    public User updatePassword(User user, String password) {
        user.setPassword(passwordEncoder.encode(password));
        return update(user);
    }

    // 封禁用户
    @Override
    public User disableUser(User user){
        user.setEnabled(false);
        return update(user);
    }

    @Override
    public void generateRandomUsernameByStudentID(User user, String id) {
        user.getUserAuth().setStudentID(id);
        user.setUsername(usernameEncoder.encode(id));
    }

    @Override
    public String getUsernameByStudentId(String studentId) {
        return usernameEncoder.encode(studentId);
    }

    @Override
    public void generateRandomUsername(User user) {
        user.setUsername(usernameEncoder.encode(UUID.randomUUID().toString()));
    }

    @Override
    public User save(User user) {
        // 查找用户名是否已经被注册
        if(userRepository.findByUsername(user.getUsername()).isPresent())
            throw new UsernameAlreadyExistException(user.getUsername());

        // 用户关键信息一般性规范检查
        if(user.getUserAuth().getUserAnswer() == null
                || user.getUserAuth().getUserQuestion() == null
                || user.getUserAuth().getStudentID() == null
                || user.getUserDetail().getRealName() == null
                || user.getUserAuth().getMail() == null){
            throw new RuntimeException("Some Key Information IS NULL");
        }


        // 用户信息一般性规范检查
        if(user.getUserAuth().getUserAnswer().length() > 255
                || user.getUserAuth().getUserQuestion().length() > 255
                || user.getUserAuth().getStudentID().length() > 24
                || user.getUserAuth().getMail().length() > 64
                || user.getUserDetail().getRealName().length() > 64)
            throw new UserInformationIllegalException(user.getUsername());

        // 强制以哈希值(sha256)保存密码
        user.setPassword(passwordEncoder.encode(user.getPassword()));
        return userRepository.save(user);
    }

    @Override
    public User update(User user) {
        // 执行前检查
        if(!userRepository.findById(user.getId()).isPresent())
            throw new UserNotFoundException(user.getId(), user.getUsername());
        return userRepository.save(user);

    }

    @Override
    public void delete(User user) {
        // 执行前检查
        if(!userRepository.findById(user.getId()).isPresent())
            throw new UserNotFoundException(user.getId(), user.getUsername());
        userRepository.delete(user);
    }

    // 获得一个默认初始化的用户对象
    @Override
    public User getDefaultUser() {
        return new User();
    }

    @Override
    public User createUserByStudentInfo(BaseStudentInfo studentInfo) {
        User user = getDefaultUser();
        // 根据学生id生成用户名
        generateRandomUsernameByStudentID(user, studentInfo.getStudentId());
        // 填充用户基本信息
        user.getUserAuth().setStudentID(studentInfo.getStudentId());
        user.getUserDetail().setClassId(studentInfo.getClassId());
        user.getUserDetail().setRealName(studentInfo.getName());

        // 填充用户详细信息
        user.getUserDetail().setBaseAdministrativeDivision(studentInfo.getAdministrativeDivision());
        user.getUserDetail().setBaseCollege(studentInfo.getCollege());
        user.getUserDetail().setBaseMajor(studentInfo.getMajor());
        user.getUserDetail().setBaseEthnic(studentInfo.getEthnic());
        user.getUserDetail().setBasePoliticalStatus(studentInfo.getPoliticalStatus());
        user.getUserDetail().setSex(studentInfo.getSex());

        // 添加在校学生认证
        user.getUserDetail().setAtSchool(true);

        return user;
    }


}